Marine battery system with bypass and safe mode

ABSTRACT

A power storage system for a marine vehicle is provided. The power storage system includes marine battery systems configured to provide energy to a marine vehicle load. Each marine battery system includes a battery and a three-position contactor configured to operate the marine battery system in one of a connected state, a disconnected state, or a bypass state. The power storage system further includes a controller coupled to each of the marine battery systems. The controller is configured to retrieve a preferred fault action for the marine battery systems, and in response to detection of a fault condition in the marine vehicle, control at least one three-position contactor of the marine battery systems according to the preferred fault action. The preferred fault action includes operating the marine battery system in the disconnected state or operating the marine battery system in the bypass state.

FIELD

The present disclosure relates to battery systems for marine vessels,and more specifically, to systems and methods for operating the batterysystems in bypass and safe modes when adverse conditions are detected.

BACKGROUND

U.S. Pat. No. 6,046,514 discloses a bypass apparatus and method forseries connected energy storage devices. Each of the energy storagedevices coupled to a common series connection has an associated bypassunit connected thereto in parallel. A current bypass unit includes asensor which is coupled in parallel with an associated energy storagedevice or cell and senses an energy parameter indicative of an energystate of the cell, such as cell voltage. A bypass switch is coupled inparallel with the energy storage cell and operable between anon-activated state and an activated state. The bypass switch, when inthe non-activated state, is substantially non-conductive with respect tocurrent passing through the energy storage cell and, when in theactivated state, provides a bypass current path for passing current tothe series connection so as to bypass the associated cell. A controllercontrols activation of the bypass switch in response to the voltage ofthe cell deviating from a pre-established voltage setpoint. Thecontroller may be included within the bypass unit or be disposed on acontrol platform external to the bypass unit. The bypass switch may,when activated, establish a permanent or a temporary bypass currentpath.

U.S. Pat. No. 7,557,538 discloses a fast battery charger in which eachone of the battery charging sections comprises a charging branch and abypassing branch, the battery charger is provided with enhanced chargingmonitory and control circuitry and method for performance elevation withminimal additional hardware overhead.

U.S. Pat. No. 9,054,555 discloses systems and methods for charging arechargeable battery device on a marine vessel that utilize arechargeable battery device, a charger charging the battery device, anda control circuit. The control circuit calculates an amount of currentthat is available to charge the battery device based upon an amount ofcurrent that is available from the shore power source and an amount ofcurrent that is being drawn from the shore power source by devices otherthan a voltage charger and limits the amount of current being drawn bythe voltage charger to charge the battery device to an amount that isequal to or less than the calculated amount of current that is availableto charge the battery device. The control circuit can repeatedlycalculate the amount of current that is available to charge the batterydevice and limit the amount of current being drawn by a voltage chargerto charge the battery device to thereby actively adjust an amount ofcharge applied to the battery device.

U.S. Pat. No. 9,533,747 discloses a hybrid propulsion system that has aninternal combustion engine and an electric motor that each selectivelypowers a marine propulsor to propel a marine vessel. A plurality ofbatteries discharges current to power the motor. A controller isprogrammed to aggregate the recharge and/or discharge limits of aplurality of batteries and then operate the system according to a methodthat preferably prevents internal fault and disconnection of batteriesin the plurality.

The above patents are hereby incorporated by reference in theirentireties.

SUMMARY

This Summary is provided to introduce a selection of concepts that arefurther described hereinbelow in the Detailed Description. This Summaryis not intended to identify key or essential features of the claimedsubject matter, nor is it intended to be used as an aid in limiting thescope of the claimed subject matter.

According to one implementation of the present disclosure, a powerstorage system for a marine vehicle is provided. The power storagesystem includes marine battery systems configured to provide energy to amarine vehicle load. Each marine battery system includes a battery and athree-position contactor configured to operate the marine battery systemin one of a connected state, a disconnected state, or a bypass state.The power storage system further includes a controller coupled to eachof the marine battery systems. The controller is configured to retrievea preferred fault action for the marine battery systems, and in responseto detection of a fault condition in the marine vehicle, control atleast one three-position contactor of the marine battery systemsaccording to the preferred fault action. The preferred fault actionincludes operating the marine battery system in the disconnected stateor operating the marine battery system in the bypass state.

According to another implementation of the present disclosure, a methodfor operating a power storage system for a marine vehicle is provided.The method includes retrieving a preferred fault action for marinebattery systems configured to provide energy to a marine vehicle load.Each of the marine battery systems includes a battery and athree-position contactor configured to operate the marine battery systemin one of a connected state, a disconnected state, or a bypass state. Inresponse to detection of a fault condition in the marine vehicle, themethod further includes controlling at least one three-positioncontactor of the plurality of marine battery systems according to thepreferred fault action. The preferred fault action comprises operatingthe marine battery system in the disconnected state or operating themarine battery system in the bypass state.

According to yet another implementation of the present disclosure, apower storage system for a marine vehicle is provided. The power storagesystem includes marine battery systems configured to provide energy to amarine vehicle load. Each marine battery system includes a battery and athree-position contactor configured to operate the marine battery systemin one of a connected state, a disconnected state, or a bypass state.The power storage system further includes a controller coupled to eachof the marine battery systems. The controller is configured to detect atleast one of the marine battery systems has reached a minimum thresholdstate of charge, and to control an operational state of the at least oneof the marine battery systems using the three-position contactor.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described with reference to the followingFigures. The same numbers are used throughout the Figures to referencelike features and like components.

FIG. 1 is a block diagram illustrating a marine vessel including a priorart power storage system.

FIG. 2 is another block diagram of the marine vessel and prior art powerstorage system of FIG. 1.

FIG. 3 is a block diagram illustrating a marine vessel including a powerstorage system according to an exemplary implementation of the presentdisclosure.

FIG. 4 is a block diagram of the marine vessel and power storage systemof FIG. 3 operating in a bypass mode.

FIG. 5 is a block diagram of the marine vessel and power storage systemof FIG. 3 operating in a safe mode.

FIG. 6 is a block diagram illustrating a marine vessel including a powerstorage system according to another exemplary implementation of thepresent disclosure.

FIG. 7 is a flow chart of a process for operating the power storagesystems of FIG. 3 and FIG. 6.

FIG. 8 is a flow chart of a charging process that may be performed bythe power storage systems of FIG. 3 and FIG. 6.

FIG. 9A is a block diagram of a marine battery system according toanother exemplary implementation of the present disclosure.

FIG. 9B is a block diagram of the marine battery system of FIG. 9Aoperating in a bypass mode.

FIG. 9C is a block diagram of the marine battery system of FIG. 9Aoperating in a safe mode.

DETAILED DESCRIPTION

In the present description, certain terms have been used for brevity,clearness and understanding. No unnecessary limitations are to beinferred therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes only and are intended to bebroadly construed.

FIGS. 1 and 2 depict a marine vessel 10 with a conventional powerstorage system 12. The power storage system 12 is shown to include threerechargeable battery systems 14A, 14B, 14C. The battery systems 14A-14Care arranged in a series configuration and are in electricalcommunication with a load 26 to discharge current to power the load 26.In various implementations, the load 26 may be any device or system onthe marine vessel 10 that receives energy from the power storage system12. For example, the load 26 may include, but is not limited to, enginestarting systems, audio systems, windlasses, depth finders, fishlocaters, and appliances. In further implementations, the power storagesystem 12 may provide energy to a propulsion device (e.g., an electricmotor) that drive the marine vessel 10.

Each battery system 14A-14C is shown to include a positive terminal 16A,16B, 16C, a negative terminal 18A, 18B, 18C, and a battery 20A, 20B,20C. Each battery 20A-20C includes all the typical components of abattery cell, namely, a cathode, an anode, an electrolyte, and aseparator. In an exemplary implementation, each battery 20A-20C is alithium ion battery with an intercalated lithium ion compound utilizedas the cathodic material and graphite utilized as the anodic material.

Each battery system 14A-14C is further shown to include a batterymanagement system (BMS) 22A, 22B, 22C. Each BMS 22A-22C may include botha processor or processing component and a rule storage or memorycomponent. The rule storage or memory component may be any suitablestorage mechanism, including, but not limited to, ROM, RAM, or flashmemory. Each BMS 22A-22C is further shown to be communicably coupled toa switch operator 26A, 26B, 26C that controls the position of atwo-position contactor or internal disconnect relay 24A, 24B, 24C. Theswitch operators 26A-26C are configured to receive control signals fromthe BMS 22A-22C, and responsive to the control signals, to move thetwo-position contactors 24A-24C between a connected or closed position(depicted in FIG. 1) and a disconnected or open position (depicted inFIG. 2 and described in further detail below). When each of thetwo-position contactors 24A-24C in the battery systems 14A-14C are inthe connected position, the total voltage provided by the power storagesystem 12 is additive. For example, if each battery system 14A-14Cprovides a maximum of 50 V, the maximum total voltage of the powerstorage system 12 is 150 V. Although FIGS. 1 and 2 depict a powerstorage system 12 for a marine vessel 10 with three battery systems14A-14C, in an exemplary implementation, the power storage system 12 mayinclude six battery systems to provide a maximum total voltage of 300 V.

The present inventor has recognized that lithium ion batteries of thelike utilized in marine vessels are susceptible to thermal runaway,particularly if water enters a sealed battery enclosure and reacts withlithium. Thermal runaway is a potentially catastrophic condition drivenby a chain of exothermic reactions in which current flowing through thebattery causes the battery temperature to rise, which in turn increasesthe current with a further rise in temperature. In a worst casescenario, thermal runaway can result in violent combustion or explosion,therefore many lithium-based batteries include internal monitoringsystems that are configured to detect adverse conditions (e.g., batteryenclosure temperature over a maximum threshold, battery voltage over amaximum threshold, battery current over a maximum threshold) anddisconnect the batteries if a threshold is exceeded.

However, when the batteries are connected in a series configuration, asis depicted in FIGS. 1 and 2, moving any of the two-position contactors24A-24C to a disconnected position results in a complete loss ofelectrical power to the load 28 from the power storage system 12. Forexample, FIG. 2 depicts the contactor 24B in the disconnected position.This interruption creates an open circuit condition in which the voltageacross the power storage system 12 drops to 0 V. If, as is becoming morecommon, the power storage system 12 is used for electric propulsion forthe marine vessel 10, the open circuit condition can result in acomplete loss of propulsion for the marine vessel 10, potentiallystranding the marine vessel 10 in a body of water without the means toreturn to shore. The present inventor has therefore recognized that apower storage system that both protects the system against damage whenan adverse condition is detected and, if possible, prevents a total lossof propulsion in the event of a detected adverse condition would beuseful. In addition, the present inventor has recognized that a singlebattery system for marine vessels that may be safely utilized for powerstorage systems arranged in both series and parallel configurationswould be useful.

FIGS. 3-5 depict a marine vessel 100 with an improved power storagesystem 112 in a variety of operational modes. The power storage system112 is shown to include three rechargeable battery systems 114A, 114B,114C. As will be described in further detail below, FIG. 3 depicts asituation in which each of the battery systems 114A-114C of the powerstorage system 112 is operating in a connected mode, FIG. 4 depicts asituation in which the battery system 114B of the power storage system112 is operating in a bypass mode, and FIG. 5 depicts a situation inwhich each of the battery systems 114A-114C is operating in a safe mode.

The battery systems 114A-114C are shown to be arranged in a seriesconfiguration and are in electrical communication with a load 126 todischarge current to power the load 126. In an exemplary implementation,the load 126 is identical or substantially similar to the load 26 of themarine vessel 10, described above with reference to FIG. 1. For example,the load 126 may include an electric propulsion system for the marinevessel 100.

Like the battery systems 14A-14C of FIGS. 1 and 2, each of therechargeable battery systems 114A-114C is shown to include a positiveterminal 116A, 116B, 116C, a negative terminal 118A, 118B, 118C, and abattery 120A, 120B, 120C located therebetween. Each battery 120A-20Cincludes all the typical components of a battery cell, namely, acathode, an anode, an electrolyte, and a separator. In an exemplaryimplementation, each battery 120A-120C is a lithium ion battery with anintercalated lithium ion compound utilized as the cathodic material andgraphite utilized as the anodic material. In addition, each batterysystem 114A-114C is further shown to include a battery management system(BMS) 122A, 122B, 122C. Each BMS 122A-122C may include both a processoror processing component and a rule storage or memory component. The rulestorage or memory component may be any suitable storage mechanism,including, but not limited to, ROM, RAM, or flash memory. Each BMS122A-122C is shown to be communicably coupled to a switch operator 126A,126B, 126C such that the switch operators 126A-126C receive controlsignals from the BMS 122A-122C.

However, in contrast to the battery system 14A-14C of FIGS. 1 and 2,each of the rechargeable battery systems 114A-114C is shown to include athree-position contactor 124A, 124B, 124 C. Each three-positioncontactor 124A-124C is movable by the switch operators 126A-126C betweena connected or closed position (depicted in FIG. 3), a disconnected oropen position (depicted in FIG. 5) and a bypass position (depicted inFIG. 4).

As depicted in FIG. 3, when each of the three-position contactors124A-124C is in the connected position, the total voltage provided bythe power storage system 112 is additive, and if each battery system114A-114C provides a maximum of 50 V, the maximum total voltage of thepower storage system 112 is 150 V. In a typical implementation in amarine vessel, the power storage system may include six battery systemsto provide a maximum total voltage of 300 V.

Each of the rechargeable battery systems 114A-114C is further shown tobe communicably coupled to a supervisory controller 130 that is externalto the battery systems 114A-114C using a controller area network (CAN).The supervisory controller 130 may include both a processor orprocessing component and a rule storage or memory component. In anexemplary implementation, the supervisory controller 130 is configuredto monitor various systems and parameters of the marine vessel 100 and,upon detection of a fault condition (e.g., a failure of a high voltageisolation system, a break in a safety interlock loop), instruct thebattery systems 114A-114C to operate in bypass or disconnected modes,depending on the characteristics of the power storage system 112 and theseverity of the fault condition. Further details regarding this processare included below with reference to FIG. 7.

The supervisory controller 130 may be configured to store a preferredfault action for the battery systems 114A-114C. For example, if thebattery systems 114A-114C are arranged in the power storage system in aseries configuration, as is depicted in FIGS. 3-5, the supervisorycontroller 130 may be configured to command the BMS 122A-122C to movethe three-position contactors 124A-124C to a bypass position in theevent of a fault (e.g., high temperature condition, high voltagecondition, high current condition). If the battery systems 114A-114C arearranged in the power storage system in a parallel configuration, as isdepicted in FIG. 6, the supervisory controller 130 may be configured tocommand the BMS 122A-122C to move the three-position contactors124A-124C to an open position in the event of a fault. In someimplementations, the supervisory controller 130 may be omitted from thepower storage system 112, and each BMS 122A-122C may store the preferredfault action. For example, the preferred fault action could beinternally stored in each BMS 122A-122C during an installation process.

Referring now specifically to FIG. 4, the three-position contactor 124Bof the battery system 114B is shown to be in the bypass position suchthat the power storage system 112 is operating in a bypass mode. Forexample, the supervisory controller 130 may instruct the BMS 122B tooperate the switch controller 126B and move the three-position contactor124B to the bypass position because an enclosure temperature for thebattery system 114B exceeds a maximum threshold. Advantageously, movingthe three-position contactor 124B to the bypass position does not resultin an open circuit condition that cuts all power provided to the load128. Instead, battery systems 114A and 114C remain connected, such that100 V, rather than 150 V, is supplied to the load 128. If the load 128includes an electric propulsion system, this reduction in power maypermit the marine vessel 100 to “limp” to shore with reducedfunctionality. For example, the revolutions per minute (RPM) of theelectric propulsion system may be reduced. In further embodiments, ifone or more battery systems 114A-114C are operating in a bypass state,the supervisory controller 130 may reduce a charging voltage setpoint tocompensate for the reduced number of battery systems 114A-114C operatingin the connected state.

If, however, a potentially catastrophic threat to the power storagesystem 112 arises, the supervisory controller 130 may instruct every BMS122A-122C to operate the switch controllers 126A-126C and move thethree-position contactors 124A-124C to the opened position, as depictedin FIG. 5. For example, a potentially catastrophic threat to the powerstorage system 112 may arise in the event of a loss of high voltageisolation, ground faults, detection of a collision event by an impactsensor, or detection of a capsizing or sinking event by a high waterlevel sensor in the bilge. In further implementations, the supervisorycontroller 130 may command each of the three-position contactors124A-124C to the opened position at key-up to verify that each of thecontactors 124A-124C is functional. If the supervisory controller 130detects that one or more of the three-position contactors 124A-124C isnon-functional upon key-up, it may transmit a message to an operator(e.g., via a user interface on a dashboard of the marine vessel).

By moving each of the three-position contactors 124A-124C to the openedposition, a high voltage string spanning the battery systems 114A-114Cis broken up into smaller segments, eliminating a high voltage potentialon the marine vessel 100 and ensuring that the maximum voltage potentialis only that of an individual battery system 114A-114C. For example, ifeach of the battery systems 114A-114C has a maximum voltage of 50 V, bymoving each of the three-position contactors 124A-124C to the openedposition, the maximum voltage potential of the entire power storagesystem 112 is only 50 V, which is not harmful to the human body andminimizes the threat of permanent damage to the power storage system112.

FIG. 5 also depicts the power storage system 112 as including a manualstop control 132 that is coupled to each of the battery systems114A-114C using an analog input. In the event that the CAN connectionbetween the battery systems 114A-114C and the supervisory controller 130fails, or in another emergency situation, a user may operate the manualstop control 132 to move each of the three-position contactors 124A-124Cto the opened position. In alternative implementations, the manual stopcontrol 132 may be activated by lanyard, a dashboard switch, or by thesupervisory controller 130 as a back-up to a failed CAN message.

Turning now to FIG. 6, another marine vessel 600 having a power storagesystem 612 according to an exemplary implementation of the presentdisclosure is depicted. In contrast to the power storage system 112depicted in FIGS. 3-5, the power storage system 612 depicts batterysystems 114A-114C arranged in a parallel configuration with the load128. Although the three-position contactors 124A-124C of the batterysystems 114A-114C may be in the closed position under nominalconditions, when a fault condition is detected, the supervisorycontroller 130 or the manual stop control 132 may command each of thethree-position contactors 124A-124C to the opened position, as isdepicted in FIG. 6. Advantageously, identical battery systems 114A-114Cmay be utilized in both the series configuration depicted in FIGS. 3-5,and the parallel configuration depicted in FIG. 6, thus maximizinginstallation flexibility of the battery systems 114A-114C.

FIG. 7 depicts a process 700 for operating a power storage system, forexample, the power storage system 112 arranged in series depicted inFIGS. 3-5, or the power storage system 612 arranged in parallel depictedin FIG. 6. In an exemplary implementation, process 700 is performed atleast in part by the supervisory controller 130. In otherimplementations, process 700 may be performed at least in part by theBMS 122A-122C of each battery system 114A-114C. For the purpose ofsimplicity, process 700 will be described below exclusively withreference to the supervisory controller 130.

Process 700 is shown to commence with step 702, in which the supervisorycontroller 130 retrieves a preferred fault action for the power storagesystem 112, 612. In some implementations, the preferred fault action isstored in memory of the supervisory controller 130 during installationof the power storage system 112, 612. In other implementations, a usermay select and store the preferred fault action, for example, via a userinterface on the dashboard of the marine vessel. As described above, ifthe power storage system (e.g., power storage system 112) includesbattery systems (e.g., battery systems 114A-114C) arranged in a seriesconfiguration, the preferred fault action may include commanding thethree-position contactor (e.g., three-position contactors 124A-124C) toa bypass position. If the power storage system (e.g., power storagesystem 612) includes battery systems (e.g., battery systems 114A-114C)arranged in a parallel configuration, the preferred fault action mayinclude commanding the three-position contactor (e.g., three-positioncontactors 124A-124C) to an opened or disconnected position.

At step 704, the supervisory controller 130 monitors the status of themarine vessel. In various implementations, step 704 may includemonitoring the enclosure temperature, current, and voltage of thebattery systems 114A-114C. At step 706, the supervisory controller 130determines whether a fault condition has occurred in one or more of thebattery systems 114A-114C. In an exemplary implementation, thesupervisory controller 130 stores threshold values for each of themonitored parameters, and a fault condition is therefore detected whenone of the threshold values is exceeded. If the supervisory controller130 detects a fault condition at step 706, process 700 proceeds to step708, and the supervisory controller 130 performs the preferred faultaction. For example, as described above, the preferred fault action mayinclude commanding the three-position contactor 124A-124C of the one ormore battery systems 114A-114C in which the fault is detected to abypass position or to an opened position, depending on whether the powerstorage system is arranged in a series or a parallel configuration. Insome implementations, step 706 may also include transmitting a faultmessage to a user interface on the marine vessel dashboard. Once thesupervisory controller 130 has performed the one or more fault actionsat step 708, process 700 reverts to step 704, and the supervisorycontroller 130 resumes monitoring the status of the marine vessel.

If, however, the supervisory controller 130 determines at step 706 thata fault condition has not been detected, process 700 proceeds to step710, in which the supervisory controller 130 determines whether anemergency stop condition has been detected. In various implementations,step 710 may include detection of a loss of high voltage isolation, or aground fault. If the supervisory controller 130 detects an emergencystop condition at step 710, process 700 proceeds to step 712, and thesupervisory controller 120 performs the emergency stop action. In anexemplary implementation, the emergency stop action includes commandingevery three-position contactor 124A-126C of every battery system114A-114C to the opened position such that the power storage system isoperating in a safe mode, regardless of whether the power storage systemis arranged in a series or a parallel configuration. In this way, anyhigh voltage strings present in the power storage system are broken intosmaller voltage segments, each segment having a voltage level which isnot harmful to the human body. Commanding all batteries to an open statealso removes power from the battery terminals, thereby advantageouslyeliminating the possibility of arcing or external ignition. In someimplementations, step 712 may also include transmitting a fault messageto a user interface on the marine vessel dashboard or activating anaudible alert. Once the supervisory controller 130 has performed theemergency stop action at step 712, process 700 reverts to step 704, andthe supervisory controller 130 resumes monitoring the status of themarine vessel. Similarly, if the supervisory controller 130 does notdetect an emergency stop condition at step 710, process 700 concludes byreverting to step 704.

Referring now to FIG. 8, a process 800 is depicted for charging a powerstorage system, for example, the series power storage system 112depicted in FIG. 3, or the parallel power storage system 612 depicted inFIG. 6. In an exemplary implementation, process 800 is performed atleast in part by the supervisory controller 130 of the power storagesystems 112, 612. In other implementations, process 800 may be performedby a battery management system 122A-122C of one of the battery systems114A-114C. For the purpose of simplicity, process 800 will be describedbelow exclusively with reference to the supervisory controller 130.

Process 800 is shown to commence with step 802, in which the batterysystems 114A-114C of the power storage system 112 or 612 are operablycoupled to a charging source, for example, a dock pedestal. As somebattery systems charge faster than others, at step 804, the supervisorycontroller 130 detects that one or more of the battery systems 114A-114Chas reached a maximum threshold state of charge (SOC). In an exemplaryimplementation, the maximum SOC is stored in the supervisory controller130 and may be configured by an operator.

Process 800 concludes as the supervisory controller 130 commands thethree-position contactors 124A-124C associated with the one or morebattery systems 114A-114C that have reached the maximum threshold SOC.If the battery systems 114A-114C are arranged in a series configuration,the supervisory controller 130 commands the three-position contactors124A-124C to the bypass position. If the battery systems 114A-114C arearranged in a parallel configuration, the supervisory controller 130command the three-position contactors 124A-124C to the opened position.In either case, reducing the number of connected battery systems114A-114C in the power storage system 112 or 612 once a maximum SOC isachieved enables faster and more efficient charging of the entire powerstorage system 112 or 612, and prevents overcharging of a fully chargedbattery.

If the battery systems 114A-114C are arranged in a parallelconfiguration, a similar process may be implemented upon discharge ofthe power storage system 612. For example, the supervisory controller130 may monitor the SOC of each of the battery systems 114A-114Carranged in parallel and command the three-position contactors 124A-124Cfrom the closed position to the opened position once a SOC of thebattery system 114A-114C associated with the contactor drops below aminimum threshold SOC. In this way, the battery systems 114A-114C aredischarged at a relatively equal rate, and operation at a low SOC thatcould cause damage to the battery systems 114A-114C is avoided. In someimplementations, the BMS 122A-122C may be configured to automaticallycommand the three-position contactors 124A-124C to the opened positiononce a SOC drops below a minimum threshold SOC without action from thesupervisory controller 130.

Referring now to FIGS. 9A-9C, an alternative rechargeable battery system914 is depicted. In various exemplary implementations, the batterysystem 914 may be used in place of each of the marine battery systems114A-114C depicted and described above with reference to FIGS. 3-6, inboth series and parallel arrangements. Specifically, FIG. 9A depicts thebattery system 914 operating in a closed or connected state, FIG. 9Bdepicts the battery system 914 operating in a bypass state, and FIG. 9Cdepicts the battery system 914 operating in an opened or disconnectedstate.

The battery system 914 is shown to include a positive terminal 916, anegative terminal 918, and a battery 920 located therebetween. Thebattery 920 may be identical or substantially similar to the battery120A-120C, as described above. The circuit connecting the positiveterminal 916 to the negative terminal 918 across the battery 920 may beopened or closed by switch 924. In contrast to the three-positioncontactors 124A-124C described above, the switch 924 may be operable inonly two positions: closed and opened. In order to achieve the effectsof the three-position contactor 124A-124C, a second two-position switch928 is provided that acts to open or close a bypass circuit thatdirectly connects the positive terminal 916 to the negative terminal918.

When the first two-position switch 924 is in the closed position and thesecond two-position switch 928 is in the opened position, battery system914 operates in the connected state (depicted in FIG. 9A). When thefirst two-position switch 924 is in the opened position and the secondtwo-position switch 928 is in the closed position, battery system 914operates in the bypass state (depicted in FIG. 9B). When bothtwo-position switches 924 and 928 are in the opened position, batterysystem 914 operates in the disconnected state (depicted in FIG. 9C).Both two-position switches 924 and 928 may be moved between positionsaccording to instructions generated by a BMS 922 and operated by aswitch controller 926. In an exemplary implementation, the BMS 922 andthe switch controller 926 are identical or substantially similar to theBMS 122A-122C and the switch controller 126A-126C, described above withreference to FIGS. 3-6. As such, the BMS 922 operates the battery system914 according to the processes 700 and 800, described above withreference to FIGS. 7 and 8.

In the present disclosure, certain terms have been used for brevity,clearness and understanding. No unnecessary limitations are to beimplied therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes only and are intended to bebroadly construed. The different systems and methods described hereinmay be used alone or in combination with other systems and devices.Various equivalents, alternatives and modifications are possible withinthe scope of the appended claims.

1. A power storage system for a marine vehicle, comprising: a pluralityof marine battery systems configured to provide energy to a marinevehicle load, each marine battery system comprising a battery; athree-position contactor configured to operate the marine battery systemin one of a connected state, a disconnected state, or a bypass state; acontroller coupled to each of the plurality of marine battery systems,wherein the controller is configured to: retrieve a preferred faultaction for the plurality of marine battery systems; and in response todetection of a fault condition in the marine vehicle, control at leastone three-position contactor of the plurality of marine battery systemsaccording to the preferred fault action; and wherein the preferred faultaction comprises operating the marine battery system in the disconnectedstate or operating the marine battery system in the bypass state.
 2. Thepower storage system of claim 1, wherein the preferred fault actioncomprises operating the battery system in the disconnected state whenthe plurality of marine battery systems is arranged in a parallelconfiguration with the marine vehicle load.
 3. The power storage systemof claim 1, wherein the preferred fault action comprises operating thebattery system in the bypass state when the plurality of marine batterysystems is arranged in a series configuration with the marine vehicleload.
 4. The power storage system of claim 1, wherein the faultcondition comprises exceeding a battery enclosure temperature threshold.5. The power storage system of claim 1, wherein the fault conditioncomprises exceeding a voltage threshold.
 6. The power storage system ofclaim 1, wherein the fault condition comprises exceeding a currentthreshold.
 7. The power storage system of claim 1, wherein thecontroller is further configured to: in response to detection of anemergency stop condition in the marine vehicle, control each of thethree-position contactors to operate each of the plurality of marinebattery systems in the disconnected state.
 8. The power storage systemof claim 7, wherein the emergency stop condition comprises a loss ofhigh voltage isolation.
 9. The power storage system of claim 7, whereinthe emergency stop condition comprises a ground fault.
 10. A method foroperating a power storage system for a marine vehicle, the methodcomprising: retrieving a preferred fault action for a plurality ofmarine battery systems configured to provide energy to a marine vehicleload, wherein each of the plurality of marine battery systems comprisesa battery and a three-position contactor configured to operate themarine battery system in one of a connected state, a disconnected state,or a bypass state; in response to detection of a fault condition in themarine vehicle, controlling at least one three-position contactor of theplurality of marine battery systems according to the preferred faultaction; and wherein the preferred fault action comprises operating themarine battery system in the disconnected state or operating the marinebattery system in the bypass state.
 11. The method of claim 10, whereinthe preferred fault action comprises operating the battery system in thedisconnected state when the plurality of marine battery systems isarranged in a parallel configuration with the marine vehicle load. 12.The method of claim 10, wherein the preferred fault action comprisesoperating the battery system in the bypass state when the plurality ofmarine battery systems is arranged in a series configuration with themarine vehicle load.
 13. The method of claim 10, wherein the faultcondition comprises exceeding a battery enclosure temperature threshold.14. The method of claim 10, wherein the fault condition comprisesexceeding a voltage threshold.
 15. The method of claim 10, wherein thefault condition comprises exceeding a current threshold.
 16. The methodof claim 10, further comprising: in response to detection of anemergency stop condition in the marine vehicle, controlling each of thethree-position contactors to operate each of the plurality of marinebattery systems in the disconnected state.
 17. The method of claim 16,wherein the emergency stop condition comprises a loss of high voltageisolation.
 18. The method of claim 16, wherein the emergency stopcondition comprises a ground fault.
 19. A power storage system for amarine vehicle, comprising: a plurality of marine battery systemsconfigured to provide energy to a marine vehicle load, each marinebattery system comprising a battery; a three-position contactorconfigured to operate the marine battery system in one of a connectedstate, a disconnected state, or a bypass state; a controller coupled toeach of the plurality of marine battery systems, wherein the controlleris configured to: detect that at least one of the plurality of marinebattery systems has reached a minimum threshold state of charge; andcontrol an operational state of the at least one of the plurality ofmarine battery systems using the three-position contactor.
 20. The powerstorage system of claim 19, wherein: controlling the operational stateof the at least one of the plurality of marine battery systems using thethree-position contactor comprises operating the marine battery systemin the disconnected state when the plurality of marine battery systemsis arranged in a parallel configuration with the marine vehicle load;and controlling the operational state of the at least one of theplurality of marine battery systems using the three-position contactorcomprises operating the marine battery system in the bypass state whenthe plurality of marine battery systems is arranged in a seriesconfiguration with the marine vehicle load.